PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Purpose: The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure. Materials and Methods: Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05). Results: A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05). Conclusion The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin.

Purpose: The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure. Materials and Methods: Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05). Results: A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05). Conclusion The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin.

Purpose: The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure. Materials and Methods: Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05). Results: A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05). Conclusion The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Purpose: The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure. Materials and Methods: Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05). Results: A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05). Conclusion The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

OBJECTIVES: Salmonellosis outbreaks occurred at 2 restaurants 2 days apart, and an epidemiological investigation was conducted to determine whether the outbreaks were connected. METHODS: Case studies were conducted for both outbreaks. Stool samples were collected from individuals, and food samples were collected from the restaurants. Pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing analyses were performed on outbreak-related Salmonella enterica serovar Enteritidis (Salmonella Enteritidis) isolates. Traceback investigations were also conducted for the ingredients from gimbap restaurants A and B. RESULTS: In total, 106 people from gimbap restaurant A and 5 from gimbap restaurant B met the case definition. Salmonella Enteritidis was detected in samples from 2 food handlers, 22 patients, and 1 food (iceberg lettuce) at gimbap restaurant A and from 1 patient at gimbap restaurant B. According to PFGE, all isolates were identified as SEGX01.089. The molecular typing of all isolates showed the same pattern, and the genetic distance was close according to phylogenetic analysis. Eggs were the only food ingredient that was supplied to both gimbap restaurants. CONCLUSIONS The outbreaks were caused by Salmonella Enteritidis, and the source of infections was suspected to be contaminated eggs. To prevent foodborne outbreaks of Salmonella, restaurants should heat eggs sufficiently, and egg farms need to establish management systems that prevent Salmonella infections.